"Translocation" Surgery Yields Unprecedented Results

--Offers hope for patients with early-stage macular degeneration

An operation developed at Johns Hopkins to halt blinding retinal damage from
age-related macular degeneration (AMD) improved vision in nearly half of the
first 100 patients treated, according to a recent report in the American
Journal of Ophthalmology.

"Six months after surgery, 48 percent of our patients could read an
additional two lines on a standard eye chart or had vision of 20/100 or better
– enough to legally drive in the state of Maryland – and 16 percent could
read an additional six lines on the eye chart," says Eugene de Juan, M.D.,
professor of ophthalmology at Hopkins’ Wilmer Eye Institute. "No other
treatment for AMD comes even close to that. These are the best results ever
recorded."

The operation, macular translocation, moves the central, most light-sensitive
part of the retina away from an overgrowth of abnormal blood vessels that bleed
and damage retinal tissue. The procedure is useful only for people newly
diagnosed with this so-called wet form of AMD. AMD is the major cause of
blindness in people age 55 and older.

In the surgery, de Juan pinches the sclera, the white, outer skin of the
eyeball, as if it were a hollow rubber ball, then puts sutures into the side
wall of the eye to keep it pinched, shortening its length. This buckles the
retina, which lines the inner wall of the eyeball. De Juan next injects a salty
solution into the eye under the retina, causing the retina to
"blister" enough to be moved slightly without detaching it. The
average distance the retina must be moved is only about 0.3 to 0.4 millimeters
– about .01 inches.

The report, published in the October issue of the journal, chronicles results
of the procedure in 102 eyes in the first 101 consecutive patients. Patients
ranged in age from 41 to 89; 60 percent were male. Within three months following
surgery, 37 percent of the patients gained two or more lines of vision on a
standard eye chart compared to measurements taken before surgery. Within six
months following surgery, 48 percent of patients experienced similar vision
improvement, and 10 percent had vision better than 20/40.

Patients with worse preoperative vision or who developed complications, most
commonly retinal detachment, did not improve.

Other treatments for AMD include laser photocoagulation and photodynamic
therapy (PDT). In the first, a laser beam is used to destroy abnormal blood
vessels, but few patients maintain enough central vision to permit reading or
driving, and the laser could harm surrounding tissue.

Photodynamic therapy combines the use of a light-sensitive medication and a
laser light beamed into the eye. The laser is too weak by itself to have any
effect on the retina, but it activates the drug, which produces a toxic,
reactive form of oxygen that can damage the diseased tissue and blood vessels
while leaving healthy cells alone. PDT can’t restore vision, but it can halt
the progression of the disease. De Juan says the fix is temporary, and some
patients who receive PDT need surgery later.

De Juan stresses the importance of early management of AMD: "Macular
translocation is effective only for people just diagnosed. Once they’ve had
the disease for a few months, it may be too late." To date, he has
performed close to 400 of the operations.